The Sabina SCR adjustable speed drive is designed to control the speed of a DC shunt motor by armature control thoughtout its entire speed range. lSilicon rectifiers are utilized to convert AC power to DC power for operating the drive motor.  All electronic firing and feedback circuits assure the precise speed control necessary for the widely varying loads to which motor drives are subjected. The control panel operates from 460 volts AC 50/60 cycles, with power for the DC shunt motor beingdeveloped and controlled by a full wave bridge circuit comprised of silicon rectifiers and silicon controlled rectifiers ( SCR's).